Robotic Fish

Abstract

This article reviews different research and development work on robotic fishes. The Collective Dynamics and Control Laboratory at the University of Maryland has constructed two robotic fish to study bio-inspired flow sensing and control of underwater vehicles. Bio-inspired flow sensing and flow-relative control using distributed sensor measurements have been described and demonstrated with two underwater robots. Prototypes of the robotic fish have been designed for experiments to include a rigid airfoil-shaped robot and a flexible, self-propelled robot. The closed-loop control of the flexible robot comprised feedforward and feedback controls. The feedforward term accelerates the convergence of the tracking control, and the feedback term improves the tracking performance by reducing the steady-state error. Rheotaxis and speed-control experiments have demonstrated the effectiveness of the flow sensing and control algorithms. In ongoing work, teams are investigating a novel actuation approach using an internal reaction wheel for flexible fish propulsion.